PHP determines whether two strings are equal

The strncmp() function in PHP is used to compare two strings (case-sensitive) and determine whether the first n characters of the two strings are equal. .

strncmp() function is defined as follows: (Recommended learning: PHP video tutorial)

strncmp(string1,string2,length)

Parameter description:

string1 Required. Specifies the first string to compare.

string2 Required. Specifies the second string to be compared.

length Required. Specifies the number of characters of each string used in the comparison.

Return value description:

If the two strings are equal, the return value is 0

If string1 is less than string2, the return value is less than 0

If string1 is greater than string2, the return value is greater than 0

The sample code is as follows:

<?php
/* strncmp()函数比较两个字符串前n个字符是否相等
 *
 * 返回值：
 0 - 如果两个字符串相等
 <0 - 如果 string1 小于 string2
 >0 - 如果 string1 大于 string2
 */
 $str1="welcome to www.jb51.net";
 $str2="WELCOME TO WWW.JB51.NET";
 $str3="welcome to php";
 echo strncmp($str1,$str2,2);
 echo "<br/>";
 echo strncmp($str1,$str3,2);
?>

The running result is as follows:

1
0

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